Atmos Hermès: An almost perpetual movement

The astonishing crystal sphere houses a unique, almost perpetual movement developed by the Manufacture Jaeger-LeCoultre. Since 1928, the mechanism of the Atmos clock fascinates by its exceptional mode of operation with no battery, no electric current and no winding.

It lives on air by means of an ingenious principle: a hermetically sealed capsule containing a mixture of gases that expands when the temperature rises and contracts when it drops. Connected to the mainspring of the clock, the capsule acts like a concertina or bellows, thereby constantly winding the movement.

It is so sensitive that a one-degree temperature difference is enough to power it for 48 hours.